Quality of Life and Hemodynamic Effects of Switching From Hemodialysis to Hemodiafiltration: A Canadian Controlled Cohort Study

BACKGROUND: Recent randomized clinical trials have demonstrated beneficial effects of hemodiafiltration (HDF) compared with hemodialysis (HD) on mortality and hemodynamic stability. Data on quality of life in HDF compared with HD is limited. OBJECTIVE: This study aimed to determine whether patients receiving HD experience improvements in quality of life, hemodynamic and laboratory parameters after switching to HDF. DESIGN: Observational controlled cohort study. SETTING & PATIENTS: Adult patients receiving maintenance dialysis were followed for 3 months both before and after transfer to a new unit, where they received HDF. Prior to transfer, control patients were already treated by HDF. METHODS: Quality of life at baseline and follow-up was measured using the validated minutes to recovery (MR) question. Dialysis data were collected for 3 consecutive sessions monthly; laboratory values were collected monthly. Wilcoxon signed rank test and repeated measures analysis of covariance were used to evaluate pre/post transfer changes and quantile regression to identify predictors of change in recovery time. RESULTS: Of 227 patients, 82 died, were transplanted, were hospitalized or did not transfer, leaving 123 subjects and 22 controls for analysis. MR did not improve with switching to HDF, although patients with MR > 60 min before transfer experienced a significant decrease in their MR, compared with controls. There was no improvement in intradialytic hypotension with HDF. There were no differences in laboratory values before vs after switch. LIMITATIONS: Nonrandomized single-center study, including only small numbers of patients and covering a short follow-up period; hemodynamic values only evaluated over 1 week per month; residual kidney function not recorded. CONCLUSIONS: In this Canadian experience of HDF, patients remained stable with respect to several laboratory and dialysis related parameters. Switch to HDF was associated with substantially reduced recovery time in patients with MR > 60 minutes at baseline.